What octane should I use?

[Bobert540]

I recently bought an 89 650sx. The owner ran 87 and never had a problem but I was wondering if I should go higher since there are a few mods. It has a Factory brand pipe, carb jetted for pipe and the stock head was milled a little to raise compression.(Don't know exactly how much) Do you recommend using a higher octane?

 

[thegoldenboy]

If you don't know run 91. Or at least 89 if the head has been milled. it won't exceed 91 eitherway.

 

[3rdgearpinned]

Run 91 or 92, the bigger decision is which oil to run.

 

[Bobert540]

the previous owner was running the kawi marine oil. What oil do you recommend?